Key features for me are filtering and multiple windows — it can sort all my email, and open mailbox or message windows for things I consider important. Local s

Key features for me are filtering and multiple windows — it can sort all my email, and open mailbox or message windows for things I consider important. Local storage in an accessible format (Eudora uses mbox) is table stakes; roach motels need not apply. I'm still running OS X 10.6 largely because of Eudora, but some day this machine will fail, or I'll have some compelling need to ‘upgrade’, and by then I'd like to have a better option than Eudora in a VM.